1. Field of the Invention
The present invention relates to a method of manufacturing a core of a heat exchanger for use with a heat exchanger employed in an automobile, such as a condenser, an evaporator, a heater core, or a radiator.
The present application is based on Japanese Patent Applications No. Hei. 10-239171 and 10-239175, which are incorporated herein by reference.
2. Description of the Related Art
A core of a heat exchanger, such as an evaporator, is constituted by arranging in an alternating manner a plurality of corrugated outer fins made of aluminum material and a plurality of flat tubes made of aluminum material. Each of the tubes is formed by bead-butting two tube plates and brazing the thus-butted plates.
The core is usually manufactured as follows: First, slime-like flux comprising, as dispersion medium, polybutene such as that described in, e.g., Japanese Patent Publication No. Hei. 4-322896, is applied to the entirety of the surfaces of the two tube plates constituting the tube. The two tube plates are assembled into a tube while their internal surfaces become mutually opposed. The flux-coated tubes and the outer fines are arranged one by one. The tubes and outer fines, which are arranged alternately, are heated in a heating furnace, to thereby sublime the dispersion medium of flux and activate and fuse brazing filler metal. As a result, the tubes, each being assembled from the tube plates, are brazed together, and the tube plates connected to the top peaks of the corrugated outer fin are brazed, to thereby constitute the core.
As mentioned above, slime-like flux is sprayed onto the entirety of the surfaces of each tube plate, to thereby wastefully consume flux and disadvantageously add to cost.
After the respective tube plates have been coated with flux, two tube plates are assembled to a tube, and an outer fin is connected to each side of the tube. In this way, the tubes and the outer fins are arranged in an alternate manner. Assembly of the tube plates into the single tube and arrangement of the tubes and the outer fins are performed continuously, thus deteriorating working efficiency. Further, if a worker touches the flux-coated surface of the tube plate during the operation, the flux may be disadvantageously scraped away from the surface.